Plow apparatus for laying underground cable

ABSTRACT

The plow apparatus for laying underground cable includes a heavy plow blade having a laterally slotted metal tube permanently affixed to its trailing edge. The slot allows a wire, cable, etc. to be placed in the tube without need to cut the cable for insertion into the tube from one end thereof. A sleeve is removably installed within the tube, and may have an elongate slot therein. The slotted sleeve is first placed around the cable, and then slid into the tube of the plow blade. The sleeve is rotated to misalign its slot relative to the slot of the blade tube, thereby capturing the cable within the tube and sleeve. The process is reversed for cable removal, thus allowing the cable to be installed in or removed from the tube and blade without cutting the cable. The sleeve may be circumferentially closed, i.e., unslotted, if desired.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/282,075, filed Dec. 11, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to machinery for laying cable in the ground, and particularly to a plow apparatus for laying underground cable that provides an assembly for forming a narrow slit or cut in the soil and simultaneously laying a cable at the bottom of the cut.

2. Description of the Related Art

The laying and placement of cables, wires, pipes, tubes, and the like in underground installations has become increasingly common over the years. In the case of pipes and tubes this is merely a matter of practicality, as it is generally impractical to install such fluid carrying conduits above ground, particularly in populated areas. However, in many cases such below ground level installation is due to rules and regulations prohibiting or limiting above ground installations, particularly in the case of wires and cables. In other cases it produces a more attractive installation, without the unsightly overhead wires and support structure. As a result, a great many machines and devices have been developed in the past for cutting a trench or slit in the earth and laying the cable or wire therein.

Many, if not most, such machines and equipment are adapted for relatively heavy duty work, comprising hydraulically powered attachments for back hoes, power shovels, and the like. Such equipment is well suited for the laying of large capacity underground pipe and heavy cable, but is not at all suited for the laying of lighter wire, cable, and the like. While some lighter duty equipment for laying underground cable and wiring has been developed, it generally requires at least a fair amount of manual labor to carry out parts of the operation not provided by the relatively simple equipment.

Thus, a plow apparatus for laying underground cable solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The plow apparatus for laying underground cable is removably attachable to a towing vehicle, and simultaneously cuts a narrow trench, slit, or cut in the ground and guides and deposits a wire or cable at the bottom of the cut. The extremely narrow cut formed, i.e., only slightly wider than the diameter of the cable or wire, causes minimal disturbance to the soil, with the cut closing essentially completely immediately after passage of the plow blade therethrough. While the device may be constructed in any practicable size for laying cable, wire, and the like of various diameters at various depths, it is particularly well-suited for use in laying relatively light signal cable or wire at a relatively shallow depth, as in the case of so-called “electronic fences” or “invisible fences” used to retain pets in an area where no physical aboveground fence is provided.

The plow apparatus incorporates a plow blade comprising a heavy metal plate having sufficient strength and durability to cut through soil, sod, and the like without incurring any significant damage. A plurality of attachment holes is provided through the plate, enabling it to be attached at varying heights to a hitch attachment in order to cut to various depths as desired. The hitch is adapted for removable mounting to the receiver of a receiver-type trailer hitch, or to a pin or bolt installed in place of the conventional hitch ball typically installed in the hitch post adapted for installation in the receiver hitch. While the hitch is immovably affixed to the plate or blade, it is pivotally secured to the receiver hitch to allow the blade to pivot behind the towing vehicle as it turns.

The trailing edge of the plow blade includes a sturdy metal tube welded to the trailing edge, the tube having a slot disposed laterally along the length of one side. The slot allows a wire, cable, or the like to be placed within the tube without any need to cut the wire or cable for placement in the tube from one end thereof. A sleeve is removably installed within the tube. In one embodiment, the sleeve also has a longitudinal slot formed therein. Once the cable has been inserted in the blade tube through the slot in the side of the tube, the sleeve is placed over the cable through the slot in the side of the sleeve, and the sleeve is slid into the tube of the plow blade. The sleeve is then rotated to misalign its slot relative to the slot of the tube, thereby capturing the wire or cable within the tube and sleeve. The process is reversed to remove the cable from the assembly, thus allowing the cable or wire to be installed in or removed from the plow blade assembly without cutting the cable. In an alternative embodiment, the sleeve does not have a longitudinal slot. Instead, a free end of the wire, cable, or the like is inserted through the closed sleeve prior to installing the sleeve in the tube of the plow blade.

These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental, perspective view of a plow apparatus for laying underground cable according to the present invention, illustrating its operation with a towing vehicle.

FIG. 2 is an exploded perspective view of the plow apparatus for laying underground cable according to the present invention as seen from the right rear, showing attachment of the hitch tongue to the blade, the sleeve being omitted.

FIG. 3 is an exploded perspective view of the plow apparatus for laying underground cable according to the present invention as seen from the right rear, showing the slotted cable retaining sleeve used to lock the cable in place in the guide tube of the blade, the hitch being omitted.

FIG. 4A is a partial detailed top plan view in section of the guide tube and slotted cable retaining sleeve of the plow apparatus for laying underground cable according to the present invention, showing alignment of the slots to allow passage of the cable therethrough.

FIG. 4B is a partial detailed top plan view in section of the guide tube and slotted cable retaining sleeve of the plow apparatus for laying underground cable according to the present invention, showing the sleeve turned within the guide tube to misalign the slots and lock the cable in place therein.

FIG. 5 is an exploded perspective view of an alternative embodiment of the plow apparatus for laying underground cable according to the present invention, similar to FIG. 3, but having a cable retaining sleeve without a slot.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The plow apparatus for laying underground cable is a device that is removably attachable to the conventional receiver hitch of a towing vehicle. The apparatus is particularly well adapted for use in laying relatively light cable (e.g., the signal cable for a so-called “electronic or invisible fence,” or similar installations) wherein the cable or wire is not buried deeply and a relatively small and light vehicle may act as the towing vehicle.

FIG. 1 of the drawings provides an environmental perspective view of an exemplary underground cable installation using the plow apparatus 10 and a small, lightweight towing vehicle V, e.g., a small all-terrain vehicle (ATV), a lawn or garden tractor, etc. Any such vehicle is suitable, so long as it includes a towing hitch (preferably a receiver type hitch). The plow apparatus 10 generally includes a relatively heavy, rigid, and sturdy blade 12 having a hitch member 14 extending forwardly therefrom. The hitch member 14 is pivotally secured to the receiver hitch receptacle R of the towing vehicle V by a bolt or pin P. This pivotal attachment allows the plow apparatus 10 to pivot behind the towing vehicle V to avoid lateral forces thereto as the vehicle V makes turns to follow the desired path during the underground cable installation process. Alternatively, the hitch member 14 may be connected through the hitch ball attachment passage of a conventional hitch bar (not shown) removably installed in the receiver hitch receptacle R of the towing vehicle V, if so desired.

FIG. 2 is an exploded perspective view of the plow apparatus, illustrating its various components and features, the sleeve being omitted. The blade 12 includes a leading edge 16, an opposite trailing edge 18, an upper end 20, and an opposite lower end 22. The upper end 20 of the blade 12 may include a handle 24 extending therefrom, if so desired. At least a portion of the leading edge 16 may be sharpened to facilitate the cutting of the sod or soil. The sharpened portion 26 preferably extends from the lower end 22 of the blade 12, upwardly along the leading edge 16 to some point between the lower and upper ends 22 and 20. The length of the sharpened portion 26 may be adjusted as desired, depending upon the intended depth of the soil cut that is to be formed using the blade 12.

FIGS. 2 and 3 illustrate the cable or wire dispensing system of the plow apparatus 10, with FIG. 3 illustrating all of the components thereof. The trailing edge 18 of the blade 12 includes a rigid metal guide tube 28 permanently affixed thereto (e.g., welded, etc.). The guide tube 28 serves to transfer the wire or cable from an aboveground supply, downwardly along the blade 12 and into the bottom of the slit being formed by the blade 12. The guide tube 28 includes an outwardly flared upper or cable inlet end 30 to facilitate the installation of the flexible sleeve therein (discussed further below), and an opposite lower or cable outlet end 32. The lower portion 34 of the guide tube 28 has a smoothly curved, rearwardly oriented bend therein to facilitate transfer of the wire or cable from its path downwardly along the trailing edge 18 of the blade 12 to its generally horizontal orientation at the bottom of the slit formed by the blade 12, with the lower or outlet end 32 of the guide tube 28 having a narrowing or sleeve stop 36 therein (e.g., a weld bead, a crimp, etc., shown in FIG. 3) to prevent the sleeve from passing through the lower end 32 of the guide tube 28. The rearward bend of the lower portion of the guide tube 28 may be supported by a generally horizontal brace, as shown in FIGS. 2 and 3, if the lower trailing portion of the blade 12 does not extend rearwardly sufficiently for the curvature of the guide tube 28 to be attached directly thereto.

The guide tube 28 has a laterally disposed cable insertion slot 38 therein. The slot 38 extends along the entire length of the guide tube 28 from its upper end 30 to its lower end 32. Although the slot 38 is shown along the right side of the guide tube 28, it will be seen that the slot may be oriented to the left side of the tube, if desired. Preferably, the slot 38 is laterally offset to either the left side or right side of the guide tube 28, as shown in FIGS. 2 and 3. The cable insertion slot 38 allows the underground cable or wire to be placed within the tube 28 without any need to cut an otherwise continuous length of cable to do so.

The lateral placement of the cable insertion slot 38 provides some assurance that a cable or wire installed within the tube 28 will not slip outwardly from the tube 28 during the process of installing the cable in the ground. However, additional security is preferred to ensure that the cable or wire is positively retained within the tube 28 at all times until its removal therefrom is desired. This is accomplished by means of a separate sleeve 40 that is removably installable coaxially within the guide tube 28. The sleeve 40 is preferably formed of a flexible material, e.g., a nylon tube or its equivalent, and has an upper end 42 and an opposite lower end 44. A first embodiment of the sleeve 40, shown in FIGS. 3, 4A, and 4B, has a cable insertion slot 46 extending along the complete length thereof, from the upper end 42 to the lower end 44. The flexible nature of the sleeve 40 allows it to be pushed downwardly in the guide tube 28, with the lower portion of the sleeve 40 bending through the curvature 34 in the lower portion of the guide tube 28 until the lower end 44 of the sleeve 40 contacts the sleeve stop(s) 36 at the lower or outlet end 32 of the tube 28.

FIGS. 3, 4A, and 48 illustrate the procedure for installing or removing a wire or cable C to or from the guide tube 28. Initially, the unbroken continuous length of cable or wire C is inserted into the guide tube 28 of the plow apparatus 10 through the cable insertion slot 38 thereof. Once this has been accomplished, the flexible sleeve 40 is positioned above the upper end 30 of the guide tube 28 and passed around the cable or wire C by inserting the cable C through the slot 46 in the sleeve 40.

The cable insertion slots 38 and 46 may be aligned with one another as the sleeve 40 is inserted into the guide tube 28, generally as shown in the cross-sectional view of FIG. 4A. It will be seen that this alignment of the two cable insertion slots 38 and 46 will permit the cable C to be readily inserted into or removed from the guide tube 28, or to inadvertently slip from the guide tube 28 during cable installation. Accordingly, the slotted flexible sleeve 40 is rotated axially to misalign its cable insertion slot 46 relative to the cable insertion slot 38 of the guide tube 28, resulting in an installation as shown in the cross-sectional view of FIG. 4B. In practice, the flexible sleeve 40 is generally rotated about the cable or wire C to misalign its slot 46 relative to the slot 38 of the guide tube 28 before the sleeve 40 is inserted into the guide tube 28. This facilitates the procedure, as the flexible sleeve 40 is difficult to rotate once installed completely within the guide tube 28 due to the bend or curve 34 in the lower portion of the guide tube 28 and the friction between the guide tube 28 and sleeve 40.

FIG. 2 of the drawings illustrates the adjustability of the blade 12 relative to its hitch member 14. The blade 12 includes a plurality of hitch attachment passages 48 disposed laterally therethrough. The hitch attachment passages 48 may be arranged in a single generally vertical row.

The hitch member 14 may be formed from a length of rectangular section C-channel, or other suitable material, as desired. The hitch member 14 includes two mutually opposed, parallel and laterally spaced first and second lateral plates 52 a and 52 b joined by a central tongue 54. The central tongue 54 extends forward of the lateral plates 52 a and 52 b and has a towing vehicle hitch attachment passage 56 disposed through the forward end thereof for accepting the hitch pin or bolt P (FIG. 1) for removably attaching the plow apparatus 10 to the towing vehicle V. The central tongue member 54 is cut away at the rearward portion of the hitch 14, leaving a slot 58 into which the blade 12 is inserted. One or more lateral gussets 50 may be installed between the two lateral plates 52 a, 52 b to stiffen the structure. The rearward gusset bears against the leading edge 16 of the blade 12 when the blade is installed in the hitch member 14 to further minimize any movement or play between the hitch member and blade.

Each of the lateral plates 52 a, 52 b includes an upper blade attachment passage 60 a and a lower blade attachment passage 60 b that can be aligned with a pair of the corresponding vertically aligned hitch attachment passages 48 of the blade 12 when the blade 12 is attached to the hitch member 14. Thus, the height of the blade 12 may be adjusted as desired relative to the hitch member 14 by aligning the blade attachment passages 60 a, 60 b with the desired two hitch attachment passages 48 of the blade 12. Bolts 62 and corresponding nuts 64 are preferably used to secure the blade 12 within the hitch member 14 in order to preclude any looseness or play between components, but spring-loaded bail detent pins or other suitable fasteners may be used, if desired.

The plow apparatus 10 is used generally as shown in FIG. 1 of the drawings. Initially, the depth at which the wire or cable is to be laid is determined, and the hitch member 14 is bolted through a selected pair of the hitch attachment passages 48 of the blade 12 to adjust the depth of the slit in the ground. A small starter hole is then dug in the ground at the point where the cable or wire installation is to begin, if this has not been done previously. The vehicle V is positioned with its receiver hitch R just slightly forward of this starter hole, and the blade 12 is pinned to the receiver hitch R (or to a conventional hitch bar extending therefrom). A bolt, nut, and washer assembly is preferably used to attach the hitch member 14 to the towing vehicle V in order to reduce looseness and play in the assembly.

At this point, the unbroken length of continuous cable or wire C may be installed through the guide tube 28 of the plow apparatus 10, if this has not been done beforehand. The procedure is as described further above, i.e., the cable or wire C is passed laterally into the guide tube 28 through its slot 38, the sleeve 40 is positioned above the guide tube 28 and passed laterally over the cable or wire C through the slot 46, the slot 46 of the sleeve 40 is misaligned with the slot 38 of the guide tube 28, and the sleeve 40 is pushed downwardly into the guide tube 28, with misalignment of the two slots 38 and 40 preventing the wire or cable C from slipping out of the sleeve 40 and tube 28. It will be seen that there may be a certain amount of rearward pull on the cable or wire C during the installation, depending upon the feed of the cable C downwardly through the sleeve 40. This is the reason that the slot 38 is preferably positioned to the side of the sleeve 28, rather than directly to the rear. In this manner, any rearward force produced in the sleeve 28 by the wire or cable C is not applied directly to the slot 38.

When the above setup procedures have been accomplished, the towing vehicle V may be operated to drag the plow blade 12 through the ground. Preferably a second person acting as an assistant feeds the cable or wire through the guide tube 28 as the towing vehicle V is moved along the desired cable installation path. The blade 12 makes a thin furrow F in the ground as the vehicle moves forward, with the cable or wire C being fed from a spool or other supply and downwardly through the guide tube 28 where it is ultimately deposited at the bottom of the furrow F. The swivel or pivot attachment of the hitch member 14 to the towing vehicle V allows the vehicle to make turns as needed, with the plow blade 12 and its guide tube 28 pivoting as necessary to align with the path of the towing vehicle.

The process continues until the cable or wire C has been laid along the desired route or path. The very narrow furrow F (more closely resembling a slit in the ground) closes nearly completely almost immediately after passage of the plow blade 12 through the ground, depending upon the nature of the ground or soil through which the blade 12 is being drawn. Very little, if any, additional work is required to return the surface to its original appearance.

When the underground cable installation has been completed, another small hole is dug to withdraw the plow apparatus 10, and the continuous wire or cable C is removed therefrom by reversing the installation procedure described further above. The wire or cable C may then be cut to the desired length and spliced or otherwise connected to the desired electrical source to complete the task.

FIG. 5 of the drawings provides an exploded perspective view of the blade assembly wherein an alternative embodiment of the flexible sleeve is shown. The flexible sleeve 140 of FIG. 5 has a completely closed circumference, i.e., it has no slot extending along its length, as does the slotted sleeve 40 of FIGS. 3, 4A, and 4B. As the sleeve 140 does not include a slot, it will be seen that a free end of the cable or wire must initially be inserted into the upper end 142 of the sleeve to pass through the sleeve and extend from its lower end 144. This may be done with the sleeve 140 installed in its slotted guide tube 28 along the back of the blade 12, or with the sleeve 140 free of the guide tube 28.

In the event that an obstruction is encountered that interrupts the cable or wire laying procedure, the blade 12 may be raised from its furrow and the flexible sleeve 140 (with the cable or wire C remaining therein) pulled upwardly from the guide tube 28. The spool of cable or wire C may also be removed from the vehicle V, if it was previously placed thereon. This removes the cable or wire C from the vehicle V to allow the vehicle V to be repositioned as required, with the cable or wire C remaining completely free of the vehicle V during this part of the operation and without need to cut the cable or wire C. Once the vehicle V has been repositioned as required, the flexible sleeve 140 (with the unbroken cable or wire C still passing therethrough) may be reinstalled in the guide tube 28 of the blade 12 and the blade repositioned in the ground as required to continue the cable laying process.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. 

1. A plow apparatus for laying underground cable, comprising: a blade having a leading edge, a trailing edge opposite the leading edge, an upper end, and a lower end opposite the upper end; a hitch member removably attached to and extending forward from the s blade; a rigid guide tube disposed along the trailing edge of the blade, the guide tube having an upper end, a lower end opposite the upper end, and a cable insertion slot extending from the upper end to the lower end thereof; and a flexible sleeve removably disposed within the guide tube, the sleeve having an upper end and a lower end opposite the upper end.
 2. The plow apparatus for laying underground cable according to claim 1, wherein the flexible sleeve has a cable insertion slot extending from the upper end to the lower end thereof.
 3. The plow apparatus for laying underground cable according to claim 1, wherein: the blade has a plurality of hitch attachment passages disposed therethrough; and the hitch member has mutually opposed, parallel, spaced apart first and second lateral plates and a central tongue connecting the plates to one another and extending forward therefrom, the central tongue having a towing vehicle hitch attachment passage disposed therethrough, the plates having a plurality of blade attachment passages defined therein.
 4. The plow apparatus for laying underground cable according to claim 3, wherein: the hitch attachment passages of the blade are disposed in a single generally vertical row; and the blade attachment passages of the hitch member consist of an upper passage and a lower passage, the upper passage and lower passages in the hitch member being alignable with a corresponding adjacent pair of the passages in the blade.
 5. The plow apparatus for laying underground cable according to claim 1, wherein at least a portion of the leading edge of the blade is sharpened.
 6. The plow apparatus for laying underground cable according to claim 1, further including a handle extending from the upper end of the blade.
 7. The plow apparatus for laying underground cable according to claim 1, wherein: the upper end of the guide tube is flared outwardly; and the lower end of the guide tube includes a sleeve stop therein.
 8. A plow apparatus for laying underground cable, comprising: a blade having a leading edge, a trailing edge opposite the leading edge, an upper end, a lower end opposite the upper end, and a plurality of hitch attachment passages defined therein; a hitch member removably attached to and extending forward from the blade, the hitch member having: mutually opposed, parallel, spaced apart first and second lateral plates, the plates having a plurality of blade attachment passages defined therein; and a central tongue connecting the plates to one another and extending forward therefrom, the central tongue having a towing vehicle hitch attachment passage defined therein; and a rigid guide tube disposed along the trailing edge of the blade, the guide tube having an upper end and a lower end opposite the upper end.
 9. The plow apparatus for laying underground cable according to claim 8, wherein the guide tube has a laterally disposed cable insertion slot extending from the upper end to the lower end thereof, the apparatus further comprising a flexible sleeve removably disposed within the guide tube, the sleeve having an upper end and a lower end opposite the upper end.
 10. The plow apparatus for laying underground cable according to claim 9, wherein the flexible sleeve has a cable insertion slot extending from the upper end to the lower end thereof.
 11. The plow apparatus for laying underground cable according to claim 8, wherein: the hitch attachment passages of the blade are disposed in a generally vertical row; and the blade attachment passages of the hitch member consist of an upper passage and a lower passage, the upper passage and the lower passage in the hitch member being alignable with a corresponding adjacent pair of the passages in the blade.
 12. The plow apparatus for laying underground cable according to claim 8, wherein at least a portion of the leading edge of the blade is sharpened.
 13. The plow apparatus for laying underground cable according to claim 8, further including a handle extending from the upper end of the blade.
 14. The plow apparatus for laying underground cable according to claim 8, wherein: the upper end of the guide tube is flared outwardly; and the lower end of the guide tube includes a sleeve stop therein.
 15. A plow apparatus for laying underground cable, comprising: a blade having a leading edge, a trailing edge opposite the leading edge, an upper end, a lower end opposite the upper end, and a plurality of hitch attachment passages defined therein, the hitch attachment passages being disposed in a single generally vertical row; a hitch member adjustably attached to and extending forward from the blade, the hitch member having mutually opposed, parallel, spaced apart first and second lateral plates, the plates having a pair of blade attachment passages defined therein, the blade attachment passages of the plates being alignable with a corresponding pair of adjacent passages in the row of hitch attachment passages in the blade; and a rigid guide tube disposed along the trailing edge of the blade, the guide tube having an upper end and a lower end opposite the upper end.
 16. The plow apparatus for laying underground cable according to claim 15, wherein the guide tube has a laterally disposed cable insertion slot extending from the upper end to the lower end thereof, the apparatus further comprising a flexible sleeve removably disposed within the guide tube, the sleeve having an upper end, a lower end opposite the upper end, and a cable insertion slot extending from the upper end to the lower end thereof.
 17. The plow apparatus for laying underground cable according to claim 15, wherein the hitch member has a central tongue connecting the plates to one another and extending forward therefrom, the central tongue having a towing vehicle hitch attachment passage defined therein.
 18. The plow apparatus for laying underground cable according to claim 15, wherein at least a portion of the leading edge of the blade is sharpened.
 19. The plow apparatus for laying underground cable according to claim 15, further including a handle extending from the upper end of the blade.
 20. The plow apparatus for laying underground cable according to claim 15, wherein: the upper end of the guide tube is flared outwardly; and the lower end of the guide tube includes a sleeve stop therein. 